docs: def _append_seed_handle_nodes(self, seed_type: str, nodes: MaybeNodeList) -> 'Seeding':
          """Add a seeding method and returns self.
  
          :param seed_type: The seed type
          :param nodes: A node or list of nodes
          :returns: self for fluid API
          """
          return self._append_seed(seed_type, _handle_nodes(nodes))